Motor vehicle drivers and passengers prefer high-quality mechanical elements, such as measurement instruments, which have the appearance of a high-quality Swiss watch. The disadvantage of such mechanical elements is that they are normally not reconfigurable. As such, many mechanical displays, such as tachometers and mechanical speed displays, are now being replaced with displays, that is to say, generally flat components used for visualization, which show context-related content.
The problem with displays is that they appear flat and artificial. If a reconfigurable group display is turned off, it looks like a black hole without any attractive aspect. Furthermore, it is not possible to install large displays due to the conventional arrangement of displays next to mechanical devices. Yet, it is not advantageous to combine several small displays instead of using just one large display.
Alternative devices which use a mechanical movement in order to turn mechanical measurement devices and thus bring displays to the front require moving parts, making these devices complex and prone to faults.
The prior art discloses configurations in which a mechanical or electromechanical indicator instrument is partially covered with a virtual image. As an example, WO2014/125546 A1 discloses a display device, comprising the following components: a display element with a display area, visible from the front side; a reflection element which is positioned in front of the display element and has semi-transparent properties; as well as an image output device which outputs an image in the direction of the reflection element to display a virtual image. A control unit is used to control the light emission of a light-emitting element such that a part of the display area which is covered by the virtual image when viewed from front to rear is darker than the part of the display area which is not covered by the virtual image when viewed from the same angle.
US 2008 309 470 A1 describes a built-in instrument cluster for a motor vehicle having at least one display device which emits image-forming light and is arranged in a direct field of view of an observer, and at least one illuminated and/or self-illuminating electromechanical indicator device which is arranged at an angle to the display device in the observer's field of view and which is moved into the observer's field of view together with the display device by an optical combiner adapted to reflect the image-forming light of the electromechanical indicator device. To save overall depth for motor vehicle components abutting the electromechanical indicator device, the electromechanical indicator device at least partly includes light guides and/or light projectors. The optical combiner may be formed by a semi-transparent mirror, the display device being arranged behind the mirror in a viewing direction of the observer and the electromechanical indicator device being arranged below the mirror.
DE 10 2005 011 094 A1 discloses a driver information system having a control unit with a plurality of functional elements and a display unit for the graphical representation of information at least relating to the control unit. The driver information system has a plurality of display modes for displaying the information displayed on the display unit. As such, the display unit has a semi-transparent mirror arranged at an angle, wherein a display is arranged behind the semi-transparent mirror in the driver's viewing direction, and physical circular instruments for the number of revolutions and speed are arranged in the driver's reflected viewing direction.